appsettings in console application c#
public Startup()
{
var environment = Environment.GetEnvironmentVariable("ASPNETCORE_ENVIRONMENT");
configuration = new ConfigurationBuilder()
.SetBasePath(Directory.GetCurrentDirectory())
.AddJsonFile("appsettings.json", optional: false, reloadOnChange: true)
.AddJsonFile($"appsettings.{environment}.json", optional: true)
.AddEnvironmentVariables()
.Build();
}